Common materials for shafts mainly include carbon steel, alloy steel, and ductile iron. Among them, 45 steel is the most widely used carbon steel due to its good comprehensive mechanical properties, low cost, and ease of machining.
Carbon steel: such as high-quality carbon structural steels of grades 35, 45, and 50, with 45 steel being the most commonly used. Good properties can be obtained after quenching and tempering or normalizing. For shafts with relatively low stress, ordinary carbon steels such as Q235 can also be used.
Alloy steel: such as 40Cr, 20CrMnTi, and 38CrMoAlA, etc., have higher strength, wear resistance, and fatigue performance, suitable for shafts under heavy loads, high speeds, or special working conditions, but the cost is higher.
Ductile iron: suitable for shafts with complex shapes that require vibration damping (such as crankshafts and camshafts), with advantages such as low cost, good vibration absorption, and low sensitivity to stress concentration, but poor impact toughness.
In addition, stainless steel (such as 304 and 316) can be used to manufacture shafts in corrosion-resistant environments, but its strength and economy are relatively inferior to carbon steel and alloy steel.
